I use a grater for cheese or potatoes to grade the whole bar of Zote soap into a large bowl.
Now add into bowl 4 cups of each powder and run all this through a blender or food processor.
Next I put all of this in an covered gallon ice cream bucket or whatever you choose to store this in.(I do have a recipe where you can convert baking soda that you cook with into wash powder,but it is strong smelling.So if you wish you can buy the 4lb box of arm and hammer cooking baking soda and put 4 cups onto a cookie sheet and bake at 350 degrees 1 hour then right into covered storage container.I personally use this route myself.
I use 3 or 4 TBSP per load of laundry.Grease monkey clothing or baby clothing.It is safe for both and smells fresh and clean.
This is safe for the envirement and kids and is not highly perfumed.I love it and totally endorse this homemade product.